Sharon Dunn 
In Too Deep [EPUB ebook] 

A witness’s life in jeopardy…And he’ll blow his cover to protect her After one of the at-risk teens she mentors calls her for help, Sierra Monforton witnesses a drug deal-and suddenly she’s in a killer’s crosshairs. To protect her, undercover DEA agent Joseph Anderson must keep Sierra close-as her pretend boyfriend. Joseph’s assignment may be to take down a drug ring, but he’ll risk everything to ensure Sierra doesn’t get hurt.